Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no upfront commitments. The specific endpoint at `/api/v1/transactions/319` is labeled "Premium API Access" and follows the same x402 payment pattern.
The platform advertises four main categories of APIs: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure (geocoding, validation, conversion, generation). All endpoints use the x402 protocol with the "exact" payment scheme, settling in USDC (contract 0x8335…) on Base.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The x402 challenge is live and well-formed, confirming the endpoint accepts POST requests and requires a payment of 20,000 base units of USDC (i.e., $0.02 given 6 decimals). Without documentation it is unclear what request body this particular endpoint expects or what response it returns.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto price feeds and gas estimates with per-call USDC payments
- —Running data analytics queries and exporting data on a pay-as-you-go basis
- —Using utility services like geocoding and validation without subscription commitments
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access
- —Agents and bots that can settle payments via x402 on Base
- —Projects needing low-cost, no-commitment access to diverse API categories
Not for
- —Users who need detailed API documentation and request/response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Developers not set up for USDC payments on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/319 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond a landing page listing, no request/response examples, and all doc pages render only 'Connect wallet'. The specific endpoint '/api/v1/transactions/319' has no description beyond its title. This is effectively a stub listing.
Warnings
- —No API documentation available — all doc pages render only 'Connect wallet'
- —No OpenAPI or JSON schema for request/response bodies
- —The specific endpoint /api/v1/transactions/319 ('Premium API Access') has no description of what it does or what inputs it expects
- —Cannot verify what data or functionality any endpoint actually returns
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (6 decimals = $0.02)https://lowpaymentfee.com/api/v1/transactions/319
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/319
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com